Method and device for cooling compressor type refrigerating machines



Filed April 13, 1953 Jan. 1, 1957 G. CHAUSSON 2,775,374

METHOD AND DEVICE FOR COOLING COMPRESSOR TYPE REFRIGERATING MACHINES 3 Sheets-Sheet l I INVENTOR QASTQN cHA ussm/ Jan; 1, 1957 a. CHAUSSON 2,775,874

METHOD AND DEVICE FOR COOLING COMPRESSOR TYPE REFRIGERATING MACHINES 3 Sheets-Sheet 2 Filed April 13. 1953 m vENr R GASTON CHM/$190M Jan. 1, 1957 G. CHAUSSQN 2,775,374

METHOD AND DEVICE FQR COOLING COMPRESSOR TYPE REFRIGERATING MACHINES Filed April 15, 1953 5 Sheets-Sheet 5 INvENTaR GAsTaN CHA 9180A! United States Patent METHOD AND DEVICE FOR COOLING COMPRES- SOR TYPE REFRIGERATING MACHINES Gaston Chausson, Asnieres, France, assignor to Societe Anonyme des Usines Chausson, Asnieres, France, a French company Application April 13, 1953, Serial No. 348,379

6 Claims. (Cl. 62117.8)

The compressors used for producing cold suck in cold vapours of coolant fluid from the evaporator, and force them back into the condenser. The gases forced back are highly heated due to the compression. This heating offers numerous drawbacks; in particular, it is detrimental to the lubrication of moving parts and to the behaviour of these parts, it causes carbon deposits on the seats of valves and consequently a drop in efl'iciency of the refrigerating machine, which is specially important in hot countries.

In the compressors enclosed in a sealed casing, the heat evolved in the windings by the Joule effect and in the magnetic circuits by eddy currents adds to that caused by compression. This heat may become dangerous in some cases for the windings and the various electric circuits.

The present invention obviates these drawbacks by creating a method and a device for the cooling of compressor type refrigerating machines which make it possible to force back the coolant fluid in a saturated wet condition and, consequently, at the temperature corresponding to the pressure which obtains in the condenser.

In the case of compressors enclosed in a sealed shell, a good heat conducting connection exists between the motor and the cylinder heads of the compressor, so that the cooling of the windings and electric circuits is effected jointly with that of the compressor.

In accordance with the invention, coolant fluid, partly or entirely condensed, flows, by gravity, from a derivation of the condenser into the compression and/or forcing chambers of the compressor so that this condensed coolant fluid absorbs, by vaporizing, the calories evolved by the various elements of the motor and/or compressor.

According to one type of embodiment of the invention, a delivery duct starting from the cylinder head of the compressor is connected with a battery of tubes constituting the condenser; a shunt pipe placed at the upper portion of the condenser distributes the coolant fluid in the battery of tubes constituting the condenser and in a coil fastened on the same plate as the condenser, the end of which is connected with the cylinder head of the compressor.

Numerous other features of the invention will appear from the following detailed description:

Forms of embodiment of the invention are represented by way of example in the appended drawings.

Figure 1 is a sectional elevation of a compressor and its motor.

Figure 2 is a section substantially along II--II in Figure 1.

Figure 3 is an elevation of a condenser according to the invention.

Figure 4 illustrates a modification of Figure 3.

Figure 5 illustrates a second modification of Figure 3.

Figure 6 illustrates a third modification.

Figure 7 is a sectional elevation on a larger scale of 2,775,874 Patented Jan. 1, 1957 "ice a device for connecting the condenser and the shell containing the compressor and motor.

In Figure 1, a middle metal sheet 1, fastened in the sealed shell 2, carries, at its upper portion, two lateral supports 3, 4 from which vibrating blades 5, 6 are suspended, then, at its middle portion, this sheet 1 supports the elements 7 of a magnetic circuit and, at its lower portion, it carries two cylinder head elements 8, 9 in which are imbedded the two opposite cylinders 10, 11 of the compressor.

The vibrating blades 5, 6 carry, each one of them, at their free ends, a non-magnetic metal part 12, on which are strapped two permanent magnets 13, 14 the polarities of which are in opposite directions. A bar 15, secured on this movable assembly controls the pistons 16, 17 through a flexible rod 16', 17.

According to Figure 2, the gases coming from the evaporator through a filter 18 are led to the cylinders 10 and 11 by ducts 19, 20.

After compression in the cylinders, the gases enter the chamber 21, then are led, through a duct 22, to the condenser of the refrigerating apparatus.

23 designates an incoming duct for the coolant fluid in liquid phase from the condenser and used for cooling the whole compressor as explained hereinafter.

Figure 3 shows a condenser consisting of a tubular bundle 25 welded or secured by any suitable means to a plate 24 so that the calories evolved by the coolant fluid under pressure are distributed over a large exchange area.

The delivery duct 22 which is in communication with the chamber 21 of the compressor, enclosed in the shell 2, goes up along the plate 24 and is fastened thereto only at 26 and 27, i. e. at the upper portion of the plate 24. This duct supplies, on the one hand, the bundle 25 of the condenser and, on the other hand, a branch 28 which gives a communication between the duct 22 and a coil 29 mounted or fastened by any means to the plate 24 of the condenser.

The end 290 of the coil 29 enters the shell 2 and is connected with the incoming duct 23 bringing the coolant fluid into the cylinder head of the compressor.

A pressure regulator 30 is mounted in series on the duct 22 downstream with respect to the branch 28 so as to maintain a constant pressure upstream of the regulator on the forcing portion of the compressor, said pressure being always higher than that which obtains downstream of the regulator. A reservoir of the liquid 31 is mounted downstream of the condenser and is connected with the expander of the refrigerating apparatus through a duct 32.

The gases under pressure from the chamber 21 of the compressor are brought through the duct 22 to the upper portion of the condenser. The pressure regulator 30 opposes an obstacle to the passage of said gases so that a portion of them flows through the branch 28 into the coil 29, where they condense, giving ofi to the surrounding medium an important portion of their calories. There is thus formed in the coil 29 a column of liquid which determines, due to the difference in the specific gravities of the gases and liquid, a circulation of the latter which, by gravity, moves down to the base of the coil 29.

The column of cooled liquid passes, through the dutc 23, into the shell 2 then into the cylinder head of the compressor.

The compressed coolant fluid located in the chamber 21 is obliged to pass through the duct 22, since the coil 29 and consequently the duct 23 contain fluid under liquid phase. At the beginning of the operation of the compressor, it is possible that the compressed fluid' under gas phase goes through the duct 23, however, the duct 22 being preferably insulated while the coil 29 is in contact with the thermal exchanger plate 24, it appears that the fluid is rapidly condensed into said latter coil in obliging the fluid to pass only by the duct 22.

The coolant fluid, in contact with the middle metal sheet 1 and the valves closing the cylinders and 11, vaporizes and absorbs, by this transformation, the calories corresponding to the latent heat of vaporization. A cooling is thus caused of the super-heated gases forced by the compressor and, by conduction, the liquid let in by the duct 23 also absorbs the calories evolved in the magnetic and electric circuits of the compressor by eddy currents and by the Joule effect.

The cooled fluid forced back from the chamber 21 into the duct 22 is thus saturated with humidity, i. e., it contains liquid droplets in suspension, which improves the condensation and, consequently the etliciency of the refrigerating apparatus.

In Figure 4, the pressure regulator 30 of Figure 3 is replaced by a flow limiter or restrictor 33 consisting of a helical coil made of a capillary tube. The restrictor 33 causes a load loss of the order of 0.200 to 0.300 kg. of coolant fluid going to the bundle 25 which promotes the condensation in the coil 29.

The operation is identical with that described above, and the various reference numerals designate the same elements.

According to the modfication shown in Figure 5, the duct 22 supplies directly the coil 29. The bundle 25, constituting the main portion of the condenser, is supplied in shunt from a nozzle 34 placed at some distance from the top of the compressor so as to cause a load loss in the ascending branch 35 supplying the bundle 25. This arrangement makes it possible to omit the flow limiter in Figures 3 and 4. The operation is identical with the one described above.

In Figure 6, the forcing duct 22 for the coolant fluid under pressure supplies a condenser mounted on the plate 24 and constituted by tubes forming loops 36 slightly inclined with respect to the horizontal.

As previously stated, the condenser supplies a reservoir of coolant liquid 31.

Tubes 37, 38, 39 are connected, at the lowermost points of each one, or a number only of the loops 36 formed by the condenser. The tubes 37, 38 and 39 are all connected with a collector 40 which opens into the cylinder head 8, 9 of the compressor through duct 23.

The gases from the compressor, arriving through the forcing duct 22 are partly liquefied in each loop of the condenser and the droplets of liquid thus formed flow by gravity in the tubes 37, 38, 39, then into the collector 40. The column of liquid formed in these tubes flows, by gravity, into the cylinder heads 8, 9 and absorbs the calories in the manner described above.

Referring to Fig. 6, it should be understood that the fluid exhausted from the compressor through the duct 22 is condensed in each one of the loops 36 of the condenser, said condensed fluid constituting columns of liquid in the conduits 39, 38 and 37 in communication with the collector conduit 40 communicating with the duct 23 opening into the chamber 21. Due to gravity, the columns of liquid flow in a continuous manner into the chamber 21 from which the issued wet vapor is anew exhausted and more rapidly condensed in the loops 39-27, these operations being repeated until the full filling of the condenser which begins to feed the tank 31.

Figure 7 shows a device which makes it possible to insert the coolant liquid inlet collector 40 in the shell, and to bring out the forcing duct 22 from the latter by a single connection.

The collector 40 has a slightly larger diameter than the forcing duct 22 so that the latter may be placed concentrically inside the collector 40. A welding v41 associates the duct 22 and the collector 40 which is flared l at its end 40a to fit a frusto-conical flange 42 of an end piece 43. The end piece 43 is secured, by welding, for instance, to the shell 2 and a sleeve 44 pushes the end 40a of the collector 40 against the frusto-conical flange of the end piece 43. A cap 45, welded on the frustoconical end piece 43 and to the tube 23, and an elastic joint 46 arranged inside said cap close the end 43a of the end piece 43.

The coolant liquid, used for cooling, arrives through the collector 40, enters the chamber 47, formed around the forcing duct 22 inside the end piece 43 then flows into the duct 23 leading to the cylinder heads 8, 9.

The cap 45 welded on the frusto-conical end piece 43 prevents any loss of coolant liquid inside the shell 2. The elastic gasket 46 ensures the communication of the two tube sections 22 leading the forced gases from the compressor to the condenser and insulates them from the coolant liquid flowing down the tube 40.

Referring to Fig. 7, it will be observed that the pressure in the line 22 and the line 40 connected either to branch 29 or ducts 37, 38, 39 is the same but that the line 22 contains gas while the line 40 contains liquid, as explained hereinbefore. Consequently, the liquid flows continuously by gravity by the line 40 due to the difference of density between the liquid contained in said line 40 and of the gas contained in the line 22. The liquid contained in the line 40 acts as a plug and prevents the passage of the gas coming from the compressor by said line 40, the gas consequently being obliged to pass through the line 22.

This arrangement allows a rapid and simple loading of the shell containing the compressor and motor without requiring any long or delicate operations as two connections only have to be dismantled, namely the one corresponding to the vapour suction element and that for forcing these compressed vapours.

It is obvious that the above described device is applicable-to any one of the forms of embodiment described.

In Figures 3-5, due to the interposition of pressure regulator 30, flow restrictor 33 or nozzle connection 34, the pressure in the coils 25 reaches a suflicient value for the condensation of the coolant only when the coolant is condensed in the entire length of the coils 29. When the liquid is forced in the duct 22, the coils 29 will be completely filled before an appreciable amount of liquid can enter the coil 25. In Figure 6, the liquid forced in duct 22 would flow primarily through ducts 39, 38, and 37, before flowing to the receiver 31. It is important that the condensed coolant be entered through duct 23 a very short time after the starting of the compressor. This is obtained in Figures 3-5 due to the fact that the condensation of the coolant occurs primarily at the lower portion of the coil 29 and in Figure 6 due to the fact that the condensation occurs primarily in the lower loops 36, the condensed coolant flowing through the ducts 39, 40 and 23, as shown in Figure 7. In Figures 3-5, the level of the condensed coolant rises progressively in the coils 29 so that the volume of condensed coolant introduced inside the compressor increases progressively. In Figure 6, the -level .of the condensed coolant rises also progressively in the loops 36 and said condensed coolant flows primarily through the duct 39, then through the duct 38 and the duct 37. In Figures 3-5, when the level of the condensed coolant reaches a certain value, the pressures in the coil 29 and the coil 25 tend to equalize and, consequently, a portion of the coolant is also condensed in the coils 25. In a similar manner, when the pressure of the coolant reaches a certain value in the loops 36, a portion of the coolant, which is condensed, can flow through the receiver 31.

The invention is not limited to these examples of embodiment, as various modifications may be made thereto within its scope. In particular the invention is applicable to the cooling of compressors of all types, such as the socalled hermetic type or others. In case the driving motor and compressor are separate, the compressor only is cooled.

Similarly, the coolant fluid condenser may be of the conventional type with a bundle of finned tubes, but the condenser is always placed above the compressor for allowing a regular flow, by gravity, of the coolant fiuid condensed or partly condensed.

I claim:

1. A refrigerating unit of the compression type for a refrigerating apparatus, comprising a compressor having two compression cylinders, two cylinder heads and a carrying element for said cylinder heads and cylinders carried by said cylinder heads, said cylinder heads and carrying element providing a common inner chamber to receive gases compressed in said cylinders, and a vertical condenser including a plate, disposed above said compressor, a condenser tube in thermal contact with said plate, said condenser tube constituting successive inclined loops and being connected at its lower portion with the inner chamber of the compressor, and ducts branched at the lower portions of at least some of said successive inclined loops of the condenser tube and connected to said inner chamber of the compressor, whereby gases exhausted from said inner chamber to said condenser tube are returned to said inner chamber by said ducts primarily in liquid phase where they are vaporized and then exhausted in wet gas phase.

2. A refrigerating unit according to claim 1, comprising a collector tube communicating with the inner chamber of the compressor and with each one of the ducts branched at the lower portions of said inclined loops formed by said condenser tube.

3. A refrigerating unit according to claim 1, wherein said ducts are secured to said supporting plate in close thermal contact therewith.

4. A refrigerating unit of the compression type for a refrigeration apparatus, comprising a compressor hav ing at least one compression cylinder, a body carrying said cylinder and forming a chamber for receiving compressed gases from said cylinder and a condenser disposed above said compressor and including two condensing circuits, supply duct means connecting said chamber with the inlets of both said circuits, discharge duct means for connecting one of said circuits with the expander of the refrigeration apparatus, and discharge duct means connecting the other of said circuits with said chamber for introducing cooled liquid refrigerant thereto to cool said compressor.

5. A refrigerating unit according to claim 4 wherein said compressor is enclosed in a sealed casing, said supply duct means comprising a supply duct passing through said casing, and said discharge duct means connected with said chamber enclosing said supply duct for a portion of its length and passing through said casing in surrounding relation to said supply duct.

6. A refrigeration unit of the compression type for a refrigerating apparatus, comprising a compressor having at least one compression cylinder, a body carrying said cylinder and forming a chamber for receiving compressed gases from said cylinder, and a condenser disposed above said compressor and including a thermal conducting plate with two condenser circuits supported by and in thermal contact with said plate, a supply duct connecting said compressor chamber with the inlet of one of said condenser circuits at the upper part of said condenser, a discharge duct for connecting said one circuit to the expander of the refrigeration apparatus, the other of said circuits having an inlet at its upper end connected to said one circuit and an outlet at its lower end connected to said compressor chamber, and regulating means interposed at the inlet of said one circuit to direct some of the gases through said other circuit where they are condensed and flow by gravity of said compressor chamber in liquid phase.

References Cited in the file of this patent UNITED STATES PATENTS 2,247,950 Kucher July 1, 1941 2,333,296 Cocanour Nov. 2, 1943 2,459,311 Iarlais Jan. 18, 1949 

